vdelay

Files: vdelay.h, vdelay.c

Delay line with cubic interpolation

Functions

sp_vdelay_create(sp_vdelay **vdelay)
sp_vdelay_init(sp_data *sp, sp_vdelay *vdelay, SPFLOAT maxdel)
sp_vdelay_compute(sp_data *sp, sp_vdelay *vdelay, SPFLOAT *in, SPFLOAT *out)
sp_vdelay_destroy(sp_vdelay **vdelay)

Mandatory Parameters

maxdel: The maximum delay time, in seconds.
(Recommended value: 1.0)

Optional Parameters

del: Delay time (in seconds) that can be changed during performance. This value must not exceed the maximum delay time.
(Default value: maxdel * 0.5)
feedback: Amount of feedback in delay line. Should be in range 0-1.
(Default value: 0)

Inputs

in: Signal input.

Outputs

out: Signal out.

Other Functions:

sp_vdelay_reset(sp_data *sp, sp_vdelay *vdelay)
Resets delay buffer and delay pointer.

Example Code

#include <stdlib.h>
#include <stdio.h>
#include <time.h>
#include "soundpipe.h"

typedef struct {
    sp_osc *osc, *lfo;
    sp_ftbl *ft, *sine;
    sp_vdelay *del;
} UserData;

void process(sp_data *sp, void *udata) {
    UserData *ud = udata;
    SPFLOAT freq = 0.0, del = 0.0, osc = 0.0;
    sp_osc_compute(sp, ud->lfo, NULL, &freq);
    freq = 1.0 + (freq * 0.5);
    freq = 0.02 + (freq * 0.02);
    ud->del->del = freq;
    sp_osc_compute(sp, ud->osc, NULL, &osc);
    sp_vdelay_compute(sp, ud->del, &osc, &del);
    sp->out[0] = del * 0.5 + osc * 0.5;
}

int main() {
    UserData ud;
    sp_data *sp;
    sp_create(&sp);

    sp_vdelay_create(&ud.del);
    sp_ftbl_create(sp, &ud.ft, 2048);
    sp_osc_create(&ud.osc);
    sp_ftbl_create(sp, &ud.sine, 4096);
    sp_osc_create(&ud.lfo);

    sp_vdelay_init(sp, ud.del, 0.5);
    sp_gen_file(sp, ud.ft, "Formant04.wav");
    sp_osc_init(sp, ud.osc, ud.ft, 0);
    ud.osc->freq = sp_midi2cps(50);

    sp_gen_sine(sp, ud.sine);
    sp_osc_init(sp, ud.lfo, ud.sine, 0);
    ud.lfo->freq = 0.2;

    sp->len = 44100 * 5;
    sp_process(sp, &ud, process);

    sp_vdelay_destroy(&ud.del);
    sp_ftbl_destroy(&ud.ft);
    sp_ftbl_destroy(&ud.sine);
    sp_osc_destroy(&ud.osc);
    sp_osc_destroy(&ud.lfo);
    sp_destroy(&sp);
    return 0;
}